Raman spectra and normal coordinate analysis of the copper(II) and copper(III) complexes of biuret and oxamide

The i.r. and Raman spectra of the N-coordinated copper(II)— and copper(III)—bis(biuretato) and —bis(oxamidato) complexes have been recorded, and normal coordinate analyses have yielded a Urey—Bradley force field for the Cu(III) complexes. The biuret system undergoes little change on oxidation, characterized by ring tightening and a general increase in mode frequencies. On oxidation, the oxamide system undergoes more drastic structural changes, most notably a strengthening of the CC bond in the oxamide rings, as shown by a 19% increase in K(CC), and an increase in electron density in the OCCO framework.     

Crystal structures of bis(ethylenediamine) copper(II) diethyldithiophosphate and di(ethylenediamine)bis (diethyldithiophosphato) copper(II) thiocyanate

Journal of Structural Chemistry -     

Infrared spectra of bis(aniline) and bis (p-toluidine) metal(II) isothiocyanate complexes

The infrared spectra of eight complexes of general formula [ML₂(NCS)₂] (M = Co, Ni, Cu, Zn; L = aniline or p-toluidine) have been determined over the range 4000–4150 cm^?1. Colour, magnetic moments and IR spectra are consistent with polymeric octahedral coordination in the Co(II) and Ni(II) complexes and polymeric tetragonal coordination in the Cu(II) complexes, while the Zn(II) complexes are assigned polymeric octahedral (L = aniline) and tetrahedral (L = p-toluidine) structure on the basis of their IR spectra. Independent ¹⁵N-labelling of the nitrogen atoms of the amino and isothiocyanate groups yields assignments for the internal vibrations of both groups and enables the metal-amine and metal—isothiocyanate stretching vibrations (vM-NH₂ and vM-NCS) to be distinguished. Both vM-NH₂ and vM-NCS are metal ion dependent in the Irving-Williams sequence (Co < Ni < Cu > Zn) expected from their proposed structures while the vN-H and vN-CS vibrations are inversely related to the masses of the coordinated metal ions.     

Infrared spectra and normal coordinate analysis of 2-chloroethanol

The i.r. spectra of 2-chloroethanol and its OD-deuterated analogue have been recorded in argon and nitrogen matrices and in the gas phase. Raman spectra in the liquid state have been recorded. A vibrational assignment, supported by normal coordinate calculations, is presented. A conformational change from gauche to trans conformer was noted under the i.r. beam.     

Potassium bis(ethylenediamine)­copper(II) ferricyanide

The title compound, potassium bis(ethylenediamine‐N,N′)copper(II) hexacyanoferrate(III), K[Cu(C₂H₈N₂)₂]‐[Fe(CN)₆], contains [Cu(en)₂]²⁺ and [Fe(CN)₆]^3? complex ions, where en is ethylenediamine. The Fe^III and K⁺ ions lie on twofold axes and the Cu^II atom lies on an inversion center. The [Cu(en)₂]²⁺ ion has square‐planar coordination with a mean Cu—N distance of 1.992 (2) Å and the [Fe(CN)₆]^3? ion has distorted octahedral coordination with a mean Fe—C distance of 1.947 (2) Å.     

Infrared and Raman spectra and normal coordinate analysis of disilylchloride

Disilylchloride has been synthesized by chlorination of disilane with boron trichloride. FTIR spectra have been obtained of the vapour phase and Raman spectra of the liquid phase of this molecule. The spectra are fully assigned for the first time. A normal coordinate analysis is carried out and the refined force constants are compared to previous works on disilane, disilyliodide and silylchloride. The height of the potential energy barrier to internal rotation in disilylchloride is also evaluated.     

The determination of anionic detergents with the bis (ethylenediamine)copper(II) ion

A method is described for the determination of anionic detergents. The detergent anions are extracted into chloroform as an ion-association compound with the bis(ethylenediamine)copper(II) cation. Determinations are completed by colorimetry or atomic absorption spectrometry. With a 150-ml water sample, the limit or detection is 0.03 μg ml^-1 (as LAS) for colorimetry or 0.06 μg ml^-1 for a.a.s. The method requires only one phase separation step and is highly selective. It is directly applicable to brine and sea-water samples.     

Infrared and raman spectra,vibrational assignments,normal coordinate analysis,and ab initio calculations of methyltrifluoromethyldisulfide and bis(trifluoromethyl)disulfide

The infrared and Raman (3500-35 cm^–1) spectra of gaseous and solid methyltrifluoromethyldisulfide, CF₃SSCH₃, and bis(trifluoromethyl)disulfide, CF₃SSCF₃, have been recorded. Additionally, the Raman spectra of the neat liquids have been obtained and qualitative depolarization values have been measured. These vibrational data have been interpreted, for both molecules, on the basis that the C-S-S-C dihedral angle is approximately 90°. Vibrational assignments are given for both molecules and are supported by normal coordinate calculations utilizing ab initio Hartree-Fock gradient calculations with the 3-21G^* basis set to obtain the frequencies for the normal modes and potential energy distributions. The CH₃ and CF₃ torsional modes have been observed at 140 and 48 cm^–1, respectively, for CF₃SSCH₃, from which periodic barriers of 485 cm^–1 (1.39 kcal mol^–1) and 853 cm^–1 (2.44 kcal mol^–1), respectively, have been calculated. Complete equilibrium geometries have been determined for both molecules by ab initio calculations employing both 3–21G and 6–31G basis sets. The structural parameters for bis(trifluoromethyl)disulfide are compared to those suggested from electron diffraction studies. The results are compared to corresponding quantities obtained for some similar molecules.Taken in part from the thesis of M. M. Bergana which will be submitted to the Department of Chemistry in partial fulfillment of the Ph.D. degree.     

Infrared spectra of Pt(II) creatinine complexes. Normal coordinate analysis of creatinine and Pt(creat)2(NO2)2

Infrared spectra of creatinine (H₃CNC(NH)NHCOCH₂) (creat), cis-Pt(creat)₂(NO₂)₂ and Pt(creat)₄(CIO₄)₂ have been recorded in the range 50–4000 cm⁻¹. The fundamental vibrations for the creatinine molecule were assigned by normal coordinate analysis in the generalized valence force field approximation. The spectrum of cis-Pt(creat)₂(NO₂)₂ was interpreted by comparison with the creatinine vibrational modes. Additionally the Pt(creat)₄(ClO₄)₂ infrared spectrum has been involved to help the assignment.     

EPR study on ligand-exchange reaction between bis(diethyldiselenocarbamato)copper(II) and some bis(acetylacetonato)copper(II) complexes

The paper is a study on the formation and properties of mixed-chelate copper(II) complexes, in which one ligand is strongly covalently bound diselenocarbamate (dsc), and the other belongs to a series of differently substituted acetylacetonates (acac), all forming weak covalent bonds. Thenoyltrifluoro- and trifluoro- substituted acetylacetonates only partly form mixed-chelate complexes, stable in toluene, benzene or dichloromethane, but gradually decomposing in chloroform or carbontetrachloride by analogy with Cu(Et(2)dsc)(2) behavior in these solvents. Hexafluoro-acetylacetonato copper(II) completely turns into a mixed-chelate Cu(dsc)(hfacac), which remains unchanged for more than 8 months of monitoring in all solvents used. The stability of Cu(dsc)(hfacac) is attributed to the reduced remaining negative charge on selenium atom embarrassing the formation of weak D-A complex with haloalkanes. The obtained EPR parameters suggest significant lowering of the contribution of the 4s AO of copper(II) in the mixed-chelate complexes. It is shown that Cu(acac)(2) does not react with Cu(Et(2)dsc)(2).     

Infrared spectra of nickel(II) complexes with hydroxyacetamidoxime and ethylnitrosolic acid

The IR spectra of Ni(II) complexes with ethylnitrosolic acid [HL] and/or hydroxyacetamidoxime [H(H₂L)] are reported. Isotopic substitutions such as H/D and ⁶²Ni/⁵⁸Ni have been carried out. On the basis of the known crystal structure of [Ni(H₂L)L], the IR spectra of [Ni(H₂L)L], M¹[Ni(HL)L] (with M¹ = Cs or K), [Ni(H₂L)₂] and[NiL₂] are compared and some assignments are proposed. Assumptions on coordinate bonding in the compounds of unknown structure are made.     

Infrared spectroscopic study of copper(II) complexes with N-substituted tetrazoles

The i.r. spectra (4000-200 cm⁻¹) of N-alkyltetrazoles and their complexes with copper(II) salts CuCl₂ and Cu(NCS)₂ have been measured. Spectral criteria in the middle and far regions for the identification of tetrazole isomers and their complexes are proposed. The site of the coordination in a tetrazole molecule and supposed structure of complexes are being discussed.